| Description |
The patient is a 79 year old woman with a chief complaint of visual hallucinations. She carries a diagnosis of glaucoma and cataracts. The patient was in good health until two weeks prior to admission when she noted a black cloud in her visual field in the top central area. The cloud gradually changed into images of vivid flowers which she described as lilac colored, sometimes looking like roses. The images were intermittent lasting approximately 1 minute and occurring as many as 50 times per day. The patient realized the images were not real. She consulted her ophthalmologist and was referred to a neurologist at the Lahey Clinic. Brain CT showed no abnormality. The patient continued to have daily visual hallucinations always superimposed over the central area of her visual field. The images gradually became more varied, first flowers then images of baskets and on the day of admission she noted several full length images of woman in caps, images of girls dressed in ruffled skirts and an image of a big, plump gentleman, approximately 50 to 60 years old dressed in a jumpsuit. The images were very detailed and in color. No therapy was recommended. Past History: Significant for occasional generalized headaches, tinnitus and mild hearing loss. She had a 40 year history of hypertension treated with Dyazide. In 1950 she was hospitalized for three days following concussion. In 1958 she received electroconvulsive therapy for depression. She had a history of ethanol abuse which she stopped many years ago. Social History: Patient is widowed with no children and lives alone. Her sister is handicapped following a stroke. She graduated from high school level and she took business classes to become a secretary. Medications: Nifedapine (Procardia XL) 30 mg. p.o., q.d. (calcium channel blocker) Betoptic 0.5% 1 gtt OU b.i.d. On examination she was cheerful, attentive, and oriented to time, place and person. Cranial nerve examination showed: •Decreased visual acuity OD 20/100 OS 20/60 with arcuate nerve fiber bundle defects in the superior altitudinal fields OU. •Ishihara color testing: impaired color vision with 2/14 OD color plates correct 5/14 OS. •Pupils equal, sluggishly to light and near, •Eye movements full with no nystagmus. •Fundus exam mild optic atrophy with slight optic disc cupping (glaucoma). The remainder of the cranial nerves were intact. Limbs: normal motor strength with no drift and normal rapid fine dexterous movements of the fingers. Her gait was narrow-based and steady. She was able to tandem walk and heel and toe walk. Romberg negative. Sensory examination showed decreased pin prick sensation bilaterally in a stocking-like distribution - 2/3rds up the calf plus, decreased joint position and vibration sense in the toes and absent ankle jerk consistent with a mild motor-sensory peripheral neuropathy. Cognitive tests ruled out dementia. She did well on her memory tests and tests of executive function (i.e. frontal lobe functions), which included planning and carrying out intentional behavior. She remembered 3/3 objects and could recall 5-digits forwards and backwards. One difficulty she had was with serial 7's. She had good repetition and no abnormality of her speech. On the Boston Naming Test she was able to successfully identify 54 of 60 common objects (e.g. broom, camel, escalator), placing her performance at the mean of her age. She had no left-right confusion, finger agnosia or dyscalculia. She had no apraxia. She was able to copy a picture of a clock and draw a 3 dimensional house. The one defect detected was a specific difficulty with visuo-motor processing and encoding and retention of visual information. But, given her bilateral visual field loss, glaucoma and cataracts, it was difficult to determine to what extent these visual defects were interfering with visuomotor functions. The differential diagnosis of recurrent complex visual hallucinations in an awake person includes: 1. Medication(s) 2. Metabolic status 3. Psychiatric etiology including mania, depression, substance dependence and schizophrenia 4. Neurodegenerative diseases (e.g. Lewy Body Dementia, Alzheimer's and Parkinson's disease) 5. Release hallucinations - Charles Bonnet Syndrome An EKG showed normal sinus rhythm, axis deviation of 40 degrees and left atrial enlargement. An EEG, recorded during hallucinations, showed a question of spike activity in the parieto-occipital area. A sleep EEG was normal and ruled out epilepsy. A Brain MRI with Gadolinium showed ventricular dilation, cortical, central and cerebellar atrophy, bilateral posterior limb of internal capsule lacunes and periventricular and pontine foci of T2 hyperintensity consistent with microvascular disease. Laboratory tests showed hyponatremia with a low sodium of 121, potassium 3.2, blood urea 13, creatinine 0.9. Normal hematocrit, white blood count and coagulation factors. Liver function tests normal apart from a slightly elevated SGOT at 32. The visual hallucinations were not felt to be due to hyponatremia. They continued even when the blood sodium level was corrected to 138 with intravenous dextrose saline. A diagnosis of Release Hallucinations - The Charles Bonnet Syndrome (CBS) was made. CBS is characterized by the triad: •Complex visual hallucinations (CVH) •Ocular pathology causing visual loss and •Absence of cognitive impairment. CBS affects 12 to 15% of visually impaired patients. The hallucinations are often repetitive and stereotyped, elementary or complex, involving human figures in most cases. The patients, like the present patient, have full insight of the unrealistic character of their hallucinations. The main risk factors are old age and severe visual impairment. CVH usually involve vivid scenes of animals, flowers and people, as in this patient. They may be black and white or in color, static or dynamic and may be of normal proportions or altered in size. CVH may be episodic, periodic, or continuous and tend to be more common in the evening and at night in bed. Many individuals can stop the hallucinations by opening or closing their eyes or by deviating their gaze in another direction. See also: http://content.lib.utah.edu/cdm/ref/collection/ehsl-shw/id/87 |
